Next, go to All Apps and type in the keyword "Text Entry" to proceed to add Unikey support application to Ubuntu iBus percussion 13.10.
Activate Vietnamese input on Ubuntu 13.10 Picture 3
On the Text Entery interface , click on the "+" icon then enter the search box, Vietnamese (Unikey) to integrate Unikey into iBus and click the Add button to add it.
Activate Vietnamese input on Ubuntu 13.10 Picture 4
Finally just move Vietnamese (Unikey) with the arrow keys below the list so that Vietnamese (Unikey) ranks first, so Ubuntu will understand that Vietnamese (Unikey) is the default input method.